Integrated bias and standby power supply circuit

1. An apparatus comprising: a first switching regulator stage that receives an input voltage and provides as an output an intermediate regulated output voltage, wherein the first switching regulator stage comprises at least one inductor and at least one first switch controller that provides one or more signals to one or more switches in the first switching regulator stage to regulate the intermediate regulated output voltage; a second switching regulator stage that receives as input the intermediate regulated output voltage from the first switching regulator stage and outputs a regulated main output voltage, the second switching regulator stage comprising at least one second switch controller that provides one or more signals to one or more switches in the second switching regulator stage to regulate the main output voltage of the second regulator stage; a primary bias module that utilizes a first secondary winding coupled with the inductor of the first regulator stage to provide a primary bias output voltage to the first switch controller of the first switching regulator stage; and a secondary bias module that utilizes a second secondary winding coupled with the inductor of the first regulator stage to provide a secondary bias output voltage to the second switch controller of the second switching regulator stage, the secondary bias module configured to provide the secondary output bias voltage to the second switch controller while the second switching regulator is one of in an operational state and an off state, the secondary bias output voltage referenced to the main output voltage of the second switching regulator stage.

2. The apparatus of claim 1 , wherein the secondary bias output voltage and the main output voltage of the second switching regulator stage are referenced to a common ground.

3. The apparatus of claim 2 , wherein the second switching regulator stage further comprises a transformer, the transformer comprising a secondary winding from which the main output voltage is derived, the common ground referenced to the secondary winding side of the transformer.

4. The apparatus of claim 3 , wherein the transformer further comprises a second secondary winding from which an auxiliary output voltage is derived, the auxiliary output voltage regulated by one or more switches controlled by the switch controller of the second switching regulator stage.

5. The apparatus of claim 4 , further comprising a standby module that, in response to receiving a standby signal, shuts off switching of the one or more switches of the second switching regulator stage that regulate the main output voltage such that the main output voltage is shut off.

6. The apparatus of claim 5 , wherein the auxiliary output voltage continues to be provided via the second secondary winding of the transformer.

7. The apparatus of claim 1 , wherein the secondary bias module further comprises a linear regulator for regulating the secondary bias output voltage.

8. The apparatus of claim 7 , wherein the primary bias module further comprises a linear regulator for regulating the primary bias output voltage.

9. A system comprising: a switching power supply; a first switching regulator stage of the power supply that receives an input voltage and provides as an output an intermediate regulated output voltage, wherein the first switching regulator stage comprises at least one inductor and at least one first switch controller that provides one or more signals to one or more switches in the first switching regulator stage to regulate the intermediate regulated output voltage; a second switching regulator stage of the power supply that receives as input the intermediate regulated output voltage from the first switching regulator stage and outputs a regulated main output voltage, the second switching regulator stage comprising at least one second switch controller that provides one or more signals to one or more switches in the second switching regulator stage to regulate the main output voltage of the second regulator stage; a primary bias module that utilizes a first secondary winding coupled with the inductor of the first regulator stage to provide a primary bias output voltage to the switch controller of the first switching regulator stage; and a secondary bias module that utilizes a second secondary winding coupled with the inductor of the first regulator stage to provide a secondary bias output voltage to the second switch controller of the second switching regulator stage, the secondary bias module configured to provide the secondary bias output voltage to the second switch controller while the second switching regulator is one of in an operational state and an off state, the secondary bias output voltage referenced to the main output voltage of the second switching regulator stage.

10. The system of claim 9 , further comprising one or more electronic devices that receive regulated power from the switching power supply.

11. The system of claim 10 , wherein at least one of the one or more electronic devices comprises one of a blade server, peripheral component interconnect (“PCI”) card, personal computer, laptop, router, switch, personal digital assistant, appliance, and digital media player.

12. The system of claim 9 , wherein the second switching regulator stage further comprises a transformer, the transformer comprising a secondary winding from which the main output voltage is derived.

13. The system of claim 12 , wherein the transformer further comprises a second secondary winding from which an auxiliary output voltage is derived, the auxiliary output voltage regulated by one or more switches controlled by the switch controller of the second switching regulator stage.

14. The system of claim 9 , wherein the primary bias module further comprises a linear regulator for regulating the primary bias output voltage.

15. The system of claim 9 , wherein the secondary bias module further comprises a linear regulator for regulating the secondary bias output voltage.

16. A method comprising: receiving an input voltage at a first switching regulator stage and providing as an output an intermediate regulated output voltage, wherein the first switching regulator stage comprises at least one inductor and at least one first switch controller that provides one or more signals to one or more switches in the first switching regulator stage to regulate the intermediate regulated output voltage; receiving as an input to a second switching regulator stage the intermediate regulated output voltage from the first switching regulator stage and providing as an output a regulated main output voltage, the second switching regulator stage comprising at least one second switch controller that provides one or more signals to one or more switches in the second switching regulator stage to regulate the main output voltage of the second regulator stage; utilizing a first secondary winding coupled with the inductor of the first regulator stage to provide a primary bias output voltage to the first switch controller of the first switching regulator stage; and utilizing a second secondary winding coupled with the inductor of the first regulator stage to provide a secondary bias output voltage to the second switch controller of the second switching regulator stage, the second secondary winding configured to provide the secondary bias output voltage to the second switch controller while the second switching regulator is one of in an operational state and an off state, the secondary bias output voltage referenced to the main output voltage of the second switching regulator stage.

17. A power supply comprising: a first switching regulator stage that receives an input voltage and provides an intermediate regulated output voltage, wherein the first switching regulator stage comprises at least one inductor and at least one first switch controller that provides one or more signals to one or more switches in the first switching regulator stage to regulate the intermediate regulated output voltage; a second switching regulator stage that receives as input the intermediate regulated output voltage from the first switching regulator stage and outputs a regulated main output voltage, the second switching regulator stage comprising at least one second switch controller that provides one or more signals to one or more switches in the second switching regulator stage to regulate the main output voltage of the second regulator stage; a primary bias module that utilizes a first secondary winding coupled with the inductor of the first regulator stage to provide a primary bias output voltage to the first switch controller of the first switching regulator stage; a secondary bias module that utilizes a second secondary winding coupled with the inductor of the first regulator stage to provide a secondary bias output voltage to the second switch controller of the second switching regulator stage, the secondary bias module configured to provide the secondary output bias voltage to the second switch controller while the second switching regulator is one of in an operational state and an off state, the secondary bias output voltage referenced to the main output voltage of the second switching regulator stage; wherein the second switching regulator stage further comprises a transformer, the transformer comprising a secondary winding from which the main output voltage is derived; wherein the transformer further comprises a second secondary winding from which an auxiliary output voltage is derived, the auxiliary output voltage regulated by one or more switches controlled by the switch controller of the second switching regulator stage; and a standby module that, in response to receiving a standby signal, shuts off switching of the one or more switches of the second switching regulator stage that regulate the main output voltage such that the main output voltage is shut off.